Geographic information systems (GIS), sometimes referred to as spatial information systems (SIS), are specialized information systems to capture, modeling, storage, retrieval, sharing, manipulation, analysis and presentation of spatial data. The main entities are spatial objects. The spatial component may embody both geometry (location, shape etc.) and topology (spatial relationships such as adjacency). The special traits of a geometric object differs significantly from any standard type, such as integers and strings.
For a range k-nearest neighbor query a center point (C), consisting of the X (CX) and Y (CY) coordinate, is provided, the radius (R) is and the number of requested points (K). The result is a list of k or less than k points ordered by the minimal distance to C. For the processing all points have to be considered, and for all points the distance to C has to be calculated. With an increasing number of points the processing consumes more resources (and requires a longer amount of time to complete).